Once primarily interested in economic history, Jonathan Israel has more recently turned his attention to the intellectual roots of Western modernity in the 18th-century Enlightenment. In the 1980s, critics on the left would have told him not to bother. During that decade the Enlightenment became a prime target in the American culture wars. Postmodernists found it masculine, universalist and Eurocentric; fiscal conservatives read its texts selectively, finding value in Locke on government, or praising the free market philosophy of Adam Smith. Those were the days (to paraphrase Todd Gitlin) when the right got the White House and the left got the English departments, where the Enlightenment was seen as quaint at best and as the source of Western claims to superiority at worst.

The battles of the 1980s dimly echoed those waged over the Enlightenment during the Weimar Republic. In Davos in 1929, presenting his defence of Kant and the Enlightenment, the liberal idealist Ernst Cassirer faced down the philosopher and future Nazi Martin Heidegger. Observers claimed Heidegger won that debate. A German Jew who would go into exile four years later, Cassirer had urged his contemporaries to look into ‘that bright clear mirror fashioned by the Enlightenment’ and to abandon their false notions of progress. His classic study, The Philosophy of the Enlightenment (1932), argues that there is unity in the basic principles, despite the ostensible variety in the positions staked out by thinkers as different as Locke and Rousseau. They had in common a commitment to Newtonian science, and a belief that its laws of nature could be extended to society and to government so that both might become law-abiding and knowable. Cassirer’s view of the Enlightenment dominated historical writing as late as the 1960s, and is best represented by Peter Gay’s two magisterial volumes published in 1966 and 1969.

After Gay and Cassirer, two trends dominated Enlightenment history until Israel came on the scene. One situated the Enlightenment in a particular national context, giving little attention to the international circulation of enlightened texts and the widespread knowledge of French among the educated. Just as Europeans were forming an economic union, their common cultural legacy dropped out of the discussion. It became possible to question whether some countries had even experienced the Enlightenment. Everyone agreed there had been a Scottish Enlightenment, but sceptical historians, such as J.G.A. Pocock, asked if there had ever been an English one. People still write about the Enlightenment as experienced in a single country but they are now once again aware that ideas know only linguistic barriers. This is a lesson that Israel has learned.

The second trend was to situate the Enlightenment socially and politically within coteries, the political opposition, salons and Masonic lodges, and to locate republican tendencies among the enlightened. According to this school, the intellectual movement had its origins in the 1680s, in the response to the invigorated absolutism of Louis XIV in France and James II in England. The French Protestants who fled persecution, and Locke, who hid in the Dutch republic from agents sent by James II to capture him, were credited with formulating new ideas about religious toleration, representative government, Newtonian science and alternatives to absolutism in church and state.

With the political and international dimension restored, the cultural warriors of the left, disenchanted with postmodernism, reclaimed the Enlightenment, and this was where things stood when Israel entered the picture. For him, the unity of enlightened ideals was founded in philosophical materialism, in an atheism which allowed nature and the works of man t0 be explained solely in terms of matter in motion. All his books see a philosophical and ethical debt to Spinoza (who died in 1677) as guiding the Enlightenment project and giving momentum to its quest to establish republics based on a democratic egalitarianism. Spinoza’s conflation of God with nature, his attack on superstition and fundamentalist readings of the Bible, his denial of free will – leaving the passions simply to exist, unmoralised – set a new intellectual agenda whose effects were evident in the clandestine literature of the early 18th century and, after 1750, in the mature thought of French materialists such as Diderot, Helvétius and d’Holbach. For Israel, the true unity of the Enlightenment movement lies in what his 2001 book called a ‘Radical Enlightenment’, whose influence was fundamental, he now claims, to the French revolutionaries.*

Israel has been hailed by Dutch academics as a scholar of immense erudition. Which he is. The effect of his wide reading, however, has been to obscure the basic principles of the Western Enlightenment, and to turn its progenitors into members of warring factions. He has offered dichotomies, distinctions and differences that give the reader ever narrower glimpses of 18th-century thought, which becomes increasingly fractured and unrecognisable. Most other historians would agree that the history of the Enlightenment must incorporate Spinoza and the Dutch republic, where clandestine books, translations of English republican works and new journals – largely in French – voiced enlightened opposition to religious persecution, French absolutism and the Aristotelian philosophy taught in schools. But at the borders of the Dutch republic the similarity between Israel’s Enlightenment and that of other historians ends.

Israel postulates a schism within enlightened circles: between moderates and radicals; between deists (never mind theists) and atheists; between Spinozists and everyone else; between anti-equality moderates and egalitarian radicals; between corrupted, mystical freemasons and the rationalist Illuminati in search of world reformation; between French materialists and Rousseau. The catholicity and diversity of the enlightened, the dedication of both radicals and moderates to principles such as toleration, freedom of the press, the independence of civil society, the value of public opinion and law-bound government, and their desire to alter, if not abolish, absolutism in church and state – the Enlightenment as described by historians such as Cassirer, Gay, Daniel Mornet, Franco Venturi, Robert Darnton, John Marshall (and myself) – dissolves in Israel’s dialectical thinking.

Israel sees two Enlightenments, one radical and good, the other moderate and of mixed value at best. Born and educated in Britain, now teaching in the United States, he finds little of value in the British or American historical experience. The American Revolution failed to emancipate the slaves, and from the perspective of European and American radicals, deliberately encouraged ‘the emergence of an informal aristocracy’. The Founding Fathers, in Israel’s typology, embody the moderate Enlightenment and, possessed of no cosmopolitan impulses, were content to do the work of revolution only at home. With the exception of Jefferson, they embraced the moderate Enlightenment’s ‘commitment to upholding privilege, rank and monarchy’. As the pre-Revolutionary Mirabeau noted, the Americans embraced the prejudices of the British. Nowhere in Israel’s account are we told that in the election of 1800 Americans threw out the Federalists and turned their backs on the aristocratic values associated with them.

Unlike the moderate Enlightenment the radical Enlightenment had its basis in a materialist-determinist metaphysics, and in the most recent iteration of Israel’s thesis, the ‘warring and wholly incompatible’ moderate Enlightenment has become anti-egalitarian. Those cunning moderates, seeking to bolster and make scientific their disregard for poverty and inequality, and led by Adam Smith and Turgot, invented the dismal science of economics. Israel contrasts the imagined failure of the moderates to deliver religious toleration, curtail aristocratic privilege or ameliorate poverty, with the fiery, liberating rhetoric of Paine, d’Holbach, Diderot and Helvétius, the true heirs of Spinoza. They alone, he argues, gave us enlightened modernity. The first place in the Western world to abolish slavery, Pennsylvania, with its republican constitution, leaves Israel unimpressed. The Quakers who patrolled its borders in order to prevent owners from taking their slaves south do not merit a place in his radical pantheon; they are not secular enough. That they and the Founding Fathers – like Locke before them – actually did radical things is irrelevant because within Israel’s dialectic only ideas, and only certain ideas at that, count.

According to Israel, Anglo-Americans have made no contribution to ‘full freedom of thought’ or to ‘identifying democracy as the best form of government’. Forget Locke, or Milton, or Algernon Sydney, or the Levellers and Diggers; ditch ‘the Commonwealth tradition’ and, for good measure, the Freemasons and their many Continental devotees. The gifts of freedom and democracy originated, he argues, in the minds of Hobbes, Bayle and especially Spinoza, who were followed by various French writers of the early 18th century. The late 18th-century Continental revolutions owe their intellectual roots to that radical tradition. Thus even the American Revolution, while ‘a crucial inspiration’ for European democrats, ‘was also a disturbingly defective, truncated revolution’. To be truly radical it was necessary to combine ‘philosophical monism with democracy and a purely secular moral philosophy based on equality’.

For Israel, the dialectic of ideas manifests itself in the ‘unrelenting war’ between, on the one hand, ‘court-sponsored’ moderate Enlightenment, with its ‘Eurocentric superiority complex’ – embodied in Voltaire and the Anglo-American followers of Locke and Newton – and, on the other, the radical Enlightenment, which offered ‘an entirely new form of revolutionary consciousness’. Any theorist with sincere religious beliefs had to be a moderate. As devout if heretical Christians, Newton and Locke fall into that category, and guilt by association requires that anyone bearing the label Newtonian or Lockean must be ‘perfectly attuned to the Christian faith’. Indeed, on occasion even the Jesuits are seen as allies of these two good English Protestants. That Newtonian science triumphed in the French colleges only after the expulsion of the Jesuits in 1762 is irrelevant to Israel.

Anglo-Americans can take heart, however: Israel harbours other dislikes. He can’t stand Rousseau, describing him as hostile to radicals, as renouncing society as a whole, as a nationalist, a believer in censorship and an opponent of representative democracy – in short, as proto-totalitarian. The ‘darker side’ of the French Revolution, he claims, ‘was chiefly inspired by the Rousseauist tendency’. In addition, Rousseau’s importance has been vastly overrated. Indeed, ‘book history demonstrates that these books [by Diderot and d’Holbach] achieved a far greater penetration in the 1770s and 1780s than did Rousseau’s political and social theoretical works, or indeed any other political and social ideology.’ One can only marvel at the ignorance of the Dutch authorities who in the 1780s banned, not the writings of Diderot or d’Holbach, but Rousseau’s Social Contract.

Israel’s likes and dislikes are not unchanging. In Radical Enlightenment the Commonwealth-man John Toland and English freethinkers in general are said to have made a ‘rather substantial’ contribution to the movement, and Rousseau is treated as the intellectual equal of Spinoza and Diderot. In A Revolution of the Mind, even d’Holbach’s immense debt to Toland has been downgraded, and while mentioned briefly, Toland is missing from the index. Some obsessions never die, however. Here, d’Holbach looms larger than in Israel’s earlier books, and is wrongly credited with informing the ‘virtual materialism’ of Joseph Priestley. There is a problem here: Priestley was religious. Ah, but he is saved by his supposed association with d’Holbach, who like every true radical, derived most of his thinking from Spinoza. Priestley’s spiritual materialism was miles away from the thinking of d’Holbach, but Israel can’t bring himself to acknowledge that Priestley’s Unitarianism expressed his deep devotion to a millenarian Christianity and his detestation of atheism.

Israel’s new hero, d’Holbach, emerges as completely in the thrall of Spinoza, and also ‘openly egalitarian, democratic and anti-colonial’. The historical record is otherwise. Through the good services of John Wilkes, whom he admired greatly when they were students at Leiden, d’Holbach learned a great deal about English thought, indeed whole passages from Toland’s Letters to Serena (1704) are translated and included in his Système de la nature (1770). Israel also describes d’Holbach as a democratic republican, when he was actually a liberal, almost utopian monarchist. Though unacknowledged by Israel, his Ethocratie, ou le gouvernement fondé sur la morale (1776) contained a cri de coeur for the virtuous sovereign, ‘the guide, the pastor and the father of his subjects … just and good himself, he would command men who resemble him, reasonable citizens, docile subjects who are truly attached’ to him. D’Holbach thought Louis XVI might be his man. With the help of ‘the legislator, accommodating himself to the weakness of [men’s] minds’, ‘enlightenment, education and the sweetness of reason’ could be received from the king – hardly the thinking of someone whom Israel labels a ‘deliberate, conscious revolutionary’. Although deeply critical of the abuses perpetrated by monarchs and nobles, d’Holbach remained firmly on the side of law and order: ‘Every citizen is made to serve the country; he must give to it his talents, his reflections, his counsels … To stop the citizen from serving his country is to declare oneself the enemy of la patrie.’ Not least, d’Holbach praised the English, who offered an example of the way government could be rescued: in ‘less than two centuries’, he claimed, they ‘threw off the yoke of Rome, and the yoke of tyranny’. Finally, while Israel glorifies d’Holbach’s egalitarianism, we aren’t told that he excluded women from his Paris salon.

At the conclusion of the book, Israel sets his sights on the early phase of the French Revolution and the failure of historians to see its Spinozist roots. Not only did Spinoza lay the foundation of atheism and of modern democracy, ‘indeed, without referring to Radical Enlightenment nothing about the French Revolution makes the slightest sense, or can even begin to be provisionally explained.’ Israel tells us that, led by the late François Furet, ‘historians of the revolutionary era … have failed almost entirely’ to understand the crucial intellectual influences he now proclaims. The French clergy of the late 1780s, however, had it ‘assuredly right’: la nouvelle philosophie of the 18th century, along with Spinoza, had undermined all authority in church and state.

How can we be sure that everything good derives from Spinoza? The ‘proof lies in the controversies’. The clerical anti-Enlightenment understood clearly that Spinoza (and Bayle as well) was the originator of the ‘contagion’ undermining throne and altar. Following the methods of Leo Strauss, Israel believes that texts hold hidden meanings, an exoteric one for the common reader and an esoteric one accessible only to the trained eye. Take Spinoza. Israel treats him as an atheist, as indeed did most of his contemporaries, and not a few 20th-century scholars. Israel can quote Spinoza claiming that ‘by God I understand a being absolutely infinite, that is a substance consisting of an infinity of attributes’, and then dismiss these words. Spinoza’s true atheistical meaning could, he holds, be communicated only clandestinely. He was so cautious that even the visiting secretary of the Royal Society, Henry Oldenburg, ‘failed to perceive the essentials of his system’. Israel cannot imagine the possibility that Spinoza meant what he said, that he believed God to be a unique, infinitely extended substance, encompassing of nature. The term ‘pantheism’ works well for a philosophy infused by God or nature and Spinoza’s more astute and freethinking readers of the next generation grasped the complexity of this metaphysical construction.

Israel, however, treats Spinoza as offering a not terribly complicated version of atheism, to be distinguished from 18th-century deism. In this propensity, to remake the world in terms of either/or, Israel further echoes Strauss and his vision of a philosophical and political universe filled with warring factions, where nuance, ambiguity and self-doubt are both boring and irrelevant. One final example of his selective reading is his discussion of the doyen of 17th-century heresy-hunters, the Cambridge Platonist Ralph Cudworth. We are led to believe that Cudworth’s True Intellectual System of the Universe (1678) has an ‘obsessive preoccupation’ with Spinoza. Yet a reader is hard pressed to find a single reference to him. Instead, Cudworth obsessed about ancient, pagan atheists and about Hobbes, his contemporary and countryman. He also tells us that Spinoza’s ‘Politico-Theological Treatise, denying both these sorts of miracles, [is] inconsiderable, and not deserving here a confutation’.

Israel misses the transformations that took place within the 18th-century materialist reading of nature. In his Encyclopédie Diderot distinguished old from new Spinozism, noting that the signal characteristic of the new version lay in the ability to infuse matter with sensibility or life. Where we find 18th-century readers of Spinoza actually describing themselves as pantheists – as Toland and the Amsterdam leader of the radical phase of the Dutch Revolution of 1747-48 (and leading Freemason), Jean Rousset de Missy did – we would profit from paying close attention to what they meant. Toland tells us that he read Spinoza through the eyes of Newton’s science, and Rousset’s debt to English ideas, notions of government and forms of sociability hasn’t been disputed since I wrote about it in 1981 in my book The Radical Enlightenment.

What happened to materialism after 1750, when it gradually became vitalistic or pantheistic, transformed the course of Western metaphysics. By postulating a law-like force within history or nature, every materialist from Toland to Diderot, d’Holbach and Marx made use of the remarkable possibilities such an intellectual move permitted. Newtonian science made it possible, as they knew and acknowledged. Because universal gravitation works on all bodies from their centres, it was easy to assert that motion is inherent in matter and that Newton’s science proved it. The force of 18th-century vitalistic materialism, or what Toland and Rousset de Missy called pantheism, lay precisely in the ability of those who promoted it to champion Newtonian science while at the same time walking away from Newton’s own metaphysics – Newton himself always located the source of motion in immaterial forces of divine origin. Despite his deep religious convictions, Newton could be read by his contemporaries and subsequent generations as endorsing a world devoid of spiritual forces, composed solely of matter in motion, pulled by the force of attraction.

Unlike the postmodernists, Israel does not condemn the Enlightenment project per se; but it must be his Enlightenment. Only true radicals, and their admirers, can sit at high table, with Spinoza at its head, flanked by Hobbes and Bayle. Israel’s historical enterprise classifies in order to glorify or dismiss and seeks to undo the unity of enlightened values on which modernity actually rests.